Air conditioning method and apparatus



Oct. 1940- c. M. ASHLEY ETAL 2,218,597

AIR CONDITIONING METHOD AND APPARATUS Filed June 5, 1936 2 Sheets-Sheet1 111g. 1. fi

INVENTORS CARLYLE M ASHLEY BY $4 5 SM Wi l/UV WNW Oct. 22, 1940. C MASHLEY ETAL 2,2 55,5537

' AIR conmnomm METHOD AND APPARATUS Filed June 5, 1956 2 Sheets-Sheet 2-A TTORNE Y.

Patented Oct. 22, 194) UNITED STATES PATENT OFFICE Am CONDITIONINGMETHOD AND APPARATUS Carlyle M. Ashley, Summit, and Sam F. Shawhan,

Maplewood, N. J., assignors, by mesne assignments, to CarrierCorporation, Newark, N. 1., a e corporation of Delaware Application June5, 1936; Serial No. 83,777

6 Claims.

hotel rooms, hospital rooms, school rooms, residences and the like,effectively and economically.

It is another object of the invention to provide an improved airconditioning unit for conditionlO ing and ventilating enclosures inwhich the moisture condensed by the cooling coils of the unit isutilized effectively to subcool liquid refrigerant prior to its supplyto the evaporator coils. The evaporation of such condensate provides ahighly 15 satisfactory solution for the problem of condensate disposal,and permits the elimination of drain pipes and the like which heretoforehave rendered the installation of room cooling units time-consuming andexpensive, and have im- 20 paired the mobility of the units. 7

Applicants unit is entirely self-contained and may be installed in arelatively short time with a minimum of effort. Installation is effectedby providing a fresh air duct between the unit and 25 a source ofoutside air, such as an open window, and by plugging in an electricalconnection from the unit to a source of electrical energy. The unit isadapted to be moved readily from one location to another with verylittle work, and with 30 practically no additional expense to the owner.

v Its portability renders the unit of particular advantage for on callservice in such places as hotels, which cater to transients, and inmeeting the requirements of short-term leaseholders.

35 The evaporation of condensate not only increases the mobility of theunit, but also increases its efiiciency through evaporative subcoolingof the liquid refrigerant.

It is another object of the invention to provide 40 an air conditioningand ventilating system in which air drawn from the outdoor atmosphere iscirculated over the compressor, condenser and subcooler of the system,and is then discharged to the outdoor atmosphere, and in which other 45air drawn from the outdoor atmosphere and/or air drawn from theenclosure served by the system is circulated over the cooling coils ofthe system and is then discharged into the enclosure.

gardless of differences between. indoor and outdoor static pressures;and the low pressure fan circulates air over the compressor, condenserand subcooler of the unit.

A feature of the invention resides in the provision of a conditioningunit having a compressor, condenser, subcooler and evaporator, in whichair drawn from the outdoor atmosphere and air drawn from the enclosureserved by the unit are circulated over the coils of said evaporator, 10whereby moisture is condensed therefrom, this moisture then beingutilized to wet the heat exchange surfaces of said subcooler, other airdrawn from the outside atmosphere being circulated over said condenserand said subcooler and then being exhausted to the outdoor atmosphere,whereby refrigerant is condensed in said condenser and evaporativelysubcooled in said subcooler, and whereby the moisture condensedv fromthe air contacting said evaporator coils is cargo ried to the outsideatmosphere in vaporous form. Another feature of the invention resides inthe provision of an air conditioning unit including an evaporator, acondenser and a subcooler, moisture condensed from air contacting saidevaporator being supplied to a pan within which the subcooler isdisposed, water from said pan being sup-'- plied to the outer surfacesof said condenser whenever the level of water within the pan rises abovea predetermined point. Such distribution of water over the condenser maybe effected by a spinner carried on the shaft of a fan employed tocirculate air over the subcooler and condenser. Another feature of theinvention resides in the provision of an air conditioning andventilating unit in which two motors are employed. The' first of thesedrives a high pressure fan used for supplying air to the enclosureserved by the unit. The second motor serves to drive the compressor ofthe unit, a low pressure fan which circulates 40 outdoor air over thesubcooler and condenser of the unit, and also a spinner for distributingwater over the outer surfaces of the condenser whenever the heatdissipated in the subcooler is insufiicient to evaporate the moistureprecipitated by the cooling coils of the unit.

Other objects, features and advantages of the invention will be moreapparent from the following description to be read in connection withthe accompanying drawings in which:

Fig. 1 is a front elevational view of applicant's unit with the front ofthe casing removed;

Fig. 2 is an end elevational view of the unit of Fig. 1;

Fig. 3 is a view taken on the line 3-3 of Fig; 1;

Mg. 4 is a view taken on the line 4-4 of Fig. 1;

and

Fig. 5 is a fragmentary plan view of the unit of Figs. 1 and 2, with a,portion of the cover broken away to show the duct which supplies air tothe high pressure fan; and

Fig. 6 illustrates a modification of the invention.

Referring to the drawings, l0 designates generally the casing of an airconditioning unit having rearward section of the upper part of the unitserves as an air passageway. A duct l9 provides communication betweenthe rear of the upper portion of the unit and a source of fresh air,such as an open window or the like, as disclosed in copendingapplication, Serial No. 83,116 filed June 5, 1936. A'vertical partition23 extending crosswise of the unit and having formed therein an openingin which the fan I! is disposed, divides the unit, as viewed from thefront, into a left hand portion and a right hand portion, except thatthis partition does not extend through the upper forward portion of theunit in which the cooling coils are disposed. Fresh air duct I9 isarranged to communicate with both the left hand and right hand portionsof the unit, and is preferably provided with a partition 24 whichconstitutes, in effect, a continuation of the partition 23.

Formed within the casing I8 is a vertical conduit 25 having proximatethe top thereof an opening 26 and an opening 21. Duct 25 supplies air toa fan 28, driven by a motor 29 carried on supports 29a. Fan 28 ispreferably of the high pressure type, so that it will draw in throughthe duct [9, opening 28, and duct 25 fresh air from the outdooratmosphere, even when the static pressure of the outdoor atmosphere isrelatively low. Air from the enclosure is supplied to the fan 28 throughinlet grille I and the opening 21 in duct 25. By regulating the positionof the hingedly mounted damper 30, associated with the openings 28 and21, fresh air and air from the enclosure may be supplied to the fan 28in desired proportions. Casing l8 prevents fan 28 from drawing in airthrough any other path than through duct 25.

Fan 28 discharges into a plenum chamber 3|, extending substantiallythroughout the length of the unit. The plenum chamber 3| is providedwith a number of nozzles 32 for discharging air from the plenum atrelatively high velocity in order to induce a relatively great secondarycirculation of air withdrawn from the enclosure, through inlet grille H.In a preferred form of the invention, the nozzles 32 comprise flat, thinchambers, extending upwardly from the top of the plenum chamber andhaving a plurality of air discharge openings 33 formed therein.Preferably, the top of the nozzles 32 slopes downwardly toward the frontof the unit. Any desired number of nozzles 32 may be provided lengthwiseof the unit.

The air discharged through nozzles 32 at high velocity, induces arelatively great secondary circulation of air withdrawn, from roomserved by the unit through inlet grille Ii. This induced air passes overcoils of evaporator 34 which are positioned just inside the inlet II,and is cooled and dehurnidifled thereby. Another part of the evaporator34 is disposed within the plenum chamber 3|, preferably in the upperportion thereof, so that both the primary air discharged by fan 28 andthe secondary air induced through inlet II are separately cooled priorto mixture in the mixing chamber 60. In a preferred form of theinvention, refrigerant passes from expansion valve 35 through the rearportion of plenum chamber 3|, then through the coils adapted to cool theinduced air, and then through the front portion of the plenum chamber3|, whence it is passed to compressor l4 through suction line 35. Soundabsorbing baiiles of any desired construction are preferably positionedin the lower portion of the plenum chamber to prevent the sounds .of fan28 from reaching the enclosure served by the unit. The mixture ofprimary air and secondary air is supplied to the enclosure throughoutlet grille l2. If desired, guide vanes may be provided in chamber 80for directing the air passing to the outlet grille in a slightly forwarddirection.

Refrigerant which has been compressed by compressor I4 is condensed incondenser l3 by fresh air drawn into the unit and circulated over thecondenser |3 by fan ll. Condensing air entering the unit passes throughinlet portion 31a of the duct l9 and is discharged to the outdooratmosphere through the outlet portion 31b of the duct l9. As will beunderstood, this air also takes up heat from the compressor and itsdriving motor. Refrigerant liquefied in the condenser is supplied toliquid receiver 38 whence it passes to subcooling coil 39 disposedwithin the pan 48 in the bottom of the unit. subcooling coil 39preferably comprises a considerable length of coil, to provide arelatively great heat exchange surface. If desired, refrigerant passingfrom the receiver 38 to the subcooler coil 39 may be routed throughseveral lengths of coil, such as Na, in the air stream set up by fan H,to effect air subcooling -of the refrigerant. In a preferred form of theinvention, however, evaporative subcooling is employed. Moisturecondensed from the induced air is collected in pan 6|. Moisturecondensed from the air in the plenum chamber is collected in a pan orthe like and is delivered from the plenum chamber through a tube 82.Preferably, tube 82 is of small. diameter and is spiralled. Thus thereis no appreciable loss in the pressure of the plenum; and due to thefriction developed in the spiralled tube, the velocity of air passingfrom plenum chamber 3| through the tube 82 is so reduced thatobjectionable whistling is avoided. Moisture from pan 6| and tube 62 isdelivered tocondensate tube 4| which discharges into the pan 40. Thusrefrigerant in coil 39 is evaporatively subcooled by air discharged byfan I! and by the condensate supplied to the pan 40. The evaporativesubcooling of liquid refrigerant provides a simple, yet highlyeffective, method of disposing of moisture precipitated by the coolingcoils of the unit, which does away with the necessity for drain pipes orthe like and increases the efliciency of the unit. Whenever moisture isprecipitated by the cooling coils of the unit at a greater rate thanmoisture is condensate and further to increase the efiiclency of theunit, applicant provides a spinner "carried on the shaft driving fan l1.Spinner 42 may be of any desired construction, but preferably takes theform of a wire ring 63 adapted to be rotated through a number of spokes64 connected to its driving shaft. Whenever the liquid level in pan 80rises above a predetermined point, as for example the top of thesubcooling coils, the spinner 42 splashes water from the pan. This wateris carried to and distributed over the outer surfaces of the condenserl3 by the air stream set up by fan 11. Thus refrigerant in the condenseris evaporatively subcooled, increasing the efficiency of the unit, andthe condensate precipitated by the coils is evaporated. Condensate invaporous form is discharged to the outer atmosphere with air leaving theunit through out-' let portion 31b of the duct I9.

In the modification of the invention illustrated in Fig. 6, thepropeller fan I1 is replaced by a centrifugal fan 90 within scroll orhousing 9|. Housing 9! is mounted over, but relatively close to pan 40.An opening 92 is provided in'the fan scroll. When the liquid level inpan 40 rises, due to insufiicient evaporation of condensate by subcooler39, water passes through opening 92 into the fan housing, where it ispicked-up by the air stream of fan 90 and delivered to the condenser I3through passage 93, whereby refrigerant in the condenser isevaporatively condensed and the moisture is evaporated. Althoughpressure will be developed within the fan scroll, such pressure will beovercome by hydrostatic pressure of condensate on the opening 92. Fan 99may be driven in any desired manner, as by a separate motor or by motor15, in the latter case, it being preferred to position the motor withits axis parallel to that of the fan 99. Applicants do not restrict theinvention to any particular driving arrangement, and any desired gear,belt, or common-shaft arrangement may be used.

Since many modifications may be made in the invention without departingfrom its scope, applicants intend that the above description andaccompanying drawings be considered as illustrative only, applicantslimiting themselves only as indicated in the appended claims.

We claim:

1. The method of air conditioning an enclosure which consists in drawingoutside air from the outdoor atmosphere, passing said outside air inheat exchange relation with a volatile refrigerant whereby said outsideair is cooled and moisture is precipitated therefrom, discharging saidoutside air at high-velocity to induce a relatively great secondarycirculation of air withdrawn from said enclosure, said withdrawn airbeing passed in heat exchange relation with a volatile refrigerantwhereby said withdrawn air is cooled and moisture is precipitatedtherefrom, supplying said outside air and said withdrawn air to theenclosure, withdrawing other air from the outdoor atmosphere, passingsaid other air in heat exchange relation with said refrigerant tocondense said refrigerant, passing said other air and said moistureprecipitated from said outside air and said air withdrawn from theenclosure in heat exchange relation with the condensed refrigerant, andexhausting said other air to the outdoor atmosphere.

2. A method according to claim 1 in which moisture precipitated from theoutside air and air withdrawn from the enclosure is placed in heatexchange relation with refrigerant being cooled by said other outdoorair, whereby said refrigerant is cooled and condensed by heat transferwith said other air and by the evap oration of said precipitatedmoisture, whenever moisture is precipitated from the outside air and airwithdrawn from the enclosure at a greater rate than moisture isevaporated in the subcooling of condensed refrigerant.

3. The method of air conditioning an enclosure which consists in drawingoutside air from the outdoor atmosphere, passing said outside air inheat exchange relation with a volatile refrigerant whereby said outsideair is cooled and moisture is precipitated therefrom, discharging saidoutside air at high velocity to induce a relatively great secondarycirculation of air withdrawn from said enclosure, supplying said outsideair and said withdrawn air to the enclosure, withdrawing other air fromthe outdoor atmosphere, passing said other air in heat exchange relationwith said refrigerant to condense said refrigerant, and passing saidother air and said moisture precipitated from said outside air in heatexchange relation. with the condensed refrigerant.

4. The method of air conditioning an enclosure which consists in drawingoutside air from the outdoor atmosphere, discharging said outside air athigh velocity to induce a relatively great secondary circulation of airwithdrawn from said enclosure, said withdrawn air being passed in heatexchange relation with a volatile refrigerant whereby said withdrawn airis cooled and moisture is precipitated therefrom, supplying said outsideair and said withdrawn air to the enclosure, withdrawing other air fromthe outdoor atmosphere, passing said other air in heat exchange relationwith said refrigerant to condense said refrigerant, and passing saidother air and said moisture precipitated from said air withdrawn fromthe enclosure in heat exchange relation with the condensed refrigerant.

5. In an air conditioning unit, an evaporator,

'a condenser operatively associated with said evaporator and adapted toreceive refrigerant therefrom, a receiver adapted to receive refrigerant.from said condenser, a subcooling coil adapted to receive refrigerant,-in liquid form substantially free of gas, from the receiver, means fordelivering liquid refrigerant from the subcooling coil to theevaporator, means for circulating air in heat exchange relation with theevaporator, whereby said air is cooled and moisture is precipitatedtherefrom, means for supplying said cooled air to an enclosur'eserved bythe unit, means for circulating other air in heat exchange relation withsaid condenser and a portion of said sub-cooling coil, and means forsupplying said precipitated moisture to form a reservoir of liquidwherein another portion of the subcooling coil is located. a

6. In a unit of the character described, an evaporator, a condenseroperatively associated with said evaporator and adapted to receiverefrigerant from said evaporator, a receiver adapted to receiverefrigerant from the condenser, a subcooling coil adapted to receiveliquid refrigerant substantially free of gas from the receiver, meansfor delivering liquid refrigerant from the subcooling coil to theevaporator, means for circulating air in contact with the evaporatorwhereby said air is cooled and moistureis precipitated therefrom, meansfor supplying said cooled air to an enclosure served by the unit, 15

means for circulating air from outside said enclosure over saidcondenser and in heat exchange relation with said subcooling coil, meansfor supplying said precipitated moisture to form a liquid reservoirwherein at least a portion oi the cooling coil is positioned and meansfor supplying precipitated moisture over the outer surfaces of saidcondenser when the moisture in said reservoir rises above apredetermined minimum. CARLYLE M. ASHLEY. SAM F. SHAWHAN.

